Strep throat is a bacterial infection that causes sudden, severe pain in the throat and tonsils. It spreads easily from person to person and is especially common in children. This article explains what causes strep throat, what symptoms to watch for, and when to seek care through your family doctor or a walk-in clinic.
What Is Strep Throat?
Strep throat is caused by a type of bacteria called Group A Streptococcus. Unlike a common cold or viral sore throat, strep throat is a bacterial infection that usually requires antibiotic treatment. It can affect both children and adults, though school-age children get it most often.
The infection causes inflammation of the throat and tonsils. In some cases, it can also affect the adenoids — small glands at the back of the nose — especially in younger children. Without proper treatment, strep throat can lead to serious complications.
How Does Strep Throat Spread?
Strep throat spreads through respiratory droplets. When an infected person coughs or sneezes, tiny droplets carrying the bacteria float through the air. A nearby person can breathe these in and become infected.
You can also pick up the bacteria by touching a contaminated surface and then touching your mouth or nose. Therefore, proper hand hygiene is one of the best ways to reduce your risk. This is especially important in schools, daycares, and other group settings where children spend time together.
Other strains of Streptococcus bacteria — such as Groups C and G — can occasionally cause throat infections as well. However, Group A is by far the most common strain responsible for strep throat.
Strep Throat Symptoms to Watch For
The symptoms of strep throat tend to come on suddenly and without the typical signs of a cold. This is an important clue that helps tell strep apart from a viral sore throat.
Common Symptoms in Children and Adults
Sudden, severe sore throat with no cough or runny nose
Pain or difficulty swallowing
Fever, often above 38°C
Swollen, tender lymph nodes on the sides of the neck
White, yellow, or grey patches on the throat or tonsils
Red, swollen tonsils
General feeling of being unwell and fatigue
In contrast to strep throat, a viral sore throat usually comes along with a cough, sneezing, watery eyes, or a stuffy nose. If those cold-like symptoms are present, a virus is the more likely cause.
Scarlet Fever: A Related Condition
In some cases, a strep throat infection can cause a rough, red skin rash that starts on the neck and chest and may spread across the body. This condition is called scarlet fever. The rash feels like sandpaper to the touch.
Scarlet fever sounds alarming, but it responds well to antibiotics. When treated promptly, it is not dangerous. However, it does require a visit to your family doctor or walk-in clinic for proper diagnosis and treatment.
In teenagers and young adults, it is worth noting that infectious mononucleosis (mono) can also cause a very severe sore throat that looks similar to strep throat. Your doctor can order tests to tell the difference.
Risk Factors for Strep Throat
Anyone can get strep throat, but some people face a higher risk. Close contact with an infected person is the biggest risk factor. Children in daycares, nurseries, and elementary schools are especially vulnerable because they spend time in close quarters.
Interestingly, the size of your tonsils does not increase your risk. In fact, people who have had their tonsils and adenoids removed can still get strep throat. The tonsils are simply the most common site for the infection to take hold.
How Strep Throat Is Diagnosed
Your family doctor or walk-in clinic provider will start by reviewing your symptoms and examining your throat. They will look for redness, swelling, and any white patches on the tonsils or throat.
To confirm a strep throat diagnosis, your doctor may use a rapid strep test. This involves swabbing the back of your throat. Results are usually available within minutes. If the rapid test comes back negative but your doctor still suspects strep, they may send a throat swab to a lab for a more detailed culture test. This takes a day or two but is more thorough.
According to Health Canada, accurate diagnosis is essential before starting antibiotics. Unnecessary antibiotic use contributes to antibiotic resistance, which is a growing public health concern in Canada.
Treatment Options for Strep Throat
Strep throat is treated with antibiotics. The most commonly prescribed options include penicillin and amoxicillin, though your doctor will choose the right antibiotic for your situation. It is important to complete the full course of antibiotics, even if you start feeling better after a day or two.
Most people begin to feel significantly better within 24 to 48 hours of starting treatment. However, stopping antibiotics early can allow the bacteria to survive and may increase the risk of complications.
Managing Symptoms at Home
While antibiotics work to clear the infection, you can ease discomfort at home with a few simple measures:
Rest as much as possible
Drink plenty of warm fluids, such as herbal tea or warm water with honey
Gargle with warm salt water to soothe the throat
Use over-the-counter pain relievers like acetaminophen or ibuprofen to reduce fever and pain
Use a humidifier to add moisture to dry indoor air, especially during Canadian winters
For more guidance on managing sore throat symptoms, the Mayo Clinic’s strep throat resource offers helpful, evidence-based advice.
How Long Does Strep Throat Last?
With antibiotic treatment, most people recover within 3 to 7 days. Without antibiotics, strep throat may still resolve on its own. However, the person remains contagious even after symptoms disappear and faces a real risk of serious complications. After 48 hours of antibiotic treatment, the risk of spreading the infection drops significantly.
Possible Complications If Left Untreated
This is where strep throat differs most from a typical viral sore throat. If strep throat is not treated with antibiotics, it can lead to serious complications weeks later. These are known as post-streptococcal complications.
Possible complications include:
Rheumatic fever — a condition that can cause painful, swollen joints and lasting damage to the heart valves
Rheumatic heart disease — long-term damage to the valves of the heart
Kidney inflammation (post-streptococcal glomerulonephritis)
Rheumatic chorea — uncontrolled movements of the hands and feet
The World Health Organization’s information on rheumatic heart disease outlines how untreated strep infections remain a leading cause of preventable heart damage worldwide. In Canada, this risk is lower due to good access to healthcare, but it is still a reason to take strep throat seriously and get treated promptly.
When to See a Doctor
If you or your child has a sore throat, your first step should be to contact your family doctor. If your doctor is unavailable, a walk-in clinic can assess and treat strep throat. Most provincial health plans cover these visits.
Seek Emergency Care Right Away If You Notice
Severe throat pain rated 8 or 9 out of 10
Fever above 39°C (especially in young children)
Difficulty breathing or a sensation of gasping for air
Leaning forward to breathe more easily — this is a warning sign
Signs of confusion or delirium
Book a Same-Day or Next-Day Appointment If You Have
Severe sore throat with a fever above 38°C lasting more than 1 to 2 days
Sore throat lasting 2 to 5 days after known contact with a strep-infected person
A rough, red rash that may suggest scarlet fever
Sleep disturbances or breathing pauses at night due to swollen tonsils
Symptoms that do not improve with over-the-counter treatment
See a Doctor 1 to 2 Weeks After Recovery If You Develop
Unusual fatigue or weakness
Joint pain or swelling
Shortness of breath
A red skin rash with small bumps under the skin
Uncontrolled, involuntary movements of the arms or legs
These symptoms may point to post-streptococcal complications and need prompt medical attention. Always consult your doctor or a qualified healthcare provider before starting or stopping any treatment.
Frequently Asked Questions About Strep Throat
Is strep throat contagious?
Yes, strep throat is highly contagious. It spreads through respiratory droplets when an infected person coughs or sneezes, and also through contact with contaminated surfaces. Once you start antibiotics, your contagiousness drops significantly after about 48 hours of treatment.
Can strep throat go away on its own without antibiotics?
Strep throat can sometimes improve without antibiotics, but this approach carries real risks. Without treatment, you remain contagious even after feeling better, and you face a higher chance of developing serious complications like rheumatic fever. Canadian health guidelines recommend treating strep throat with antibiotics.
How do I know if my sore throat is strep or just a cold?
Strep throat usually comes on suddenly with a severe sore throat but without the typical cold symptoms like coughing, sneezing, or a runny nose. A cold-related sore throat is more gradual and often comes with congestion and watery eyes. A rapid strep test at your family doctor or walk-in clinic can confirm the diagnosis.
How long is strep throat contagious?
A person with untreated strep throat can remain contagious for 2 to 3 weeks, even if their symptoms have resolved. After starting a course of antibiotics, the risk of spreading strep throat drops dramatically within 24 to 48 hours. Children should generally stay home from school for at least 24 hours after beginning antibiotics.
Can adults get strep throat, or is it just a children’s illness?
Adults can absolutely get strep throat, though it is more common in school-age children. Adults who live or work with children are at higher risk. The symptoms, treatment, and potential complications of strep throat are the same for adults as they are for children.
Does strep throat require a visit to the doctor, or can I treat it at home?
Because strep throat is a bacterial infection, it requires a proper diagnosis and a prescription for antibiotics — both of which need a doctor’s visit. Home remedies like warm fluids, salt water gargles, and rest can help ease symptoms, but they will not clear the bacterial infection on their own. Visit your family doctor or a walk-in clinic if you suspect strep throat.
Key Takeaways
Strep throat is a bacterial infection caused by Group A Streptococcus bacteria.
It spreads through respiratory droplets and contact with contaminated surfaces.
Key symptoms include a sudden, severe sore throat, fever, and swollen tonsils — without cold-like symptoms such as coughing or a runny nose.
A rapid strep test at your family doctor’s office or walk-in clinic can confirm the diagnosis quickly.
Antibiotic treatment is important to prevent serious complications like rheumatic fever and heart damage.
You become much less contagious after 48 hours of antibiotic treatment.
Seek emergency care for severe symptoms, especially in young children with high fever or difficulty breathing.
Always speak with your doctor or a qualified healthcare provider before starting or stopping any medication.
